In a production line for fabricating hollow vessels, which are bottles or the like formed by blow-molding a synthetic resin or plastics, a belt conveyor or air conveyor is often used in the art as an apparatus for conveying the molded bottles.
However, a problem occurs during the conveying of bottles by a belt conveyor in that, if the conveyor apparatus is started or halted while the bottles are being conveyed, the bottles frequently fall over, and these bottles are particularly likely to fall over at a feed-screw inlet portion thereof, forcing the mechanism of the manufacturing line to halt.
The conveying of bottles by an air conveyor involves a problem in that, although it is possible to prevent the bottles from falling over because the neck portions of the bottles are suspended from rails provided in an opening in a lower surface of the wind tunnel box and an airflow from an air blower is blown against the mouth portions of the bottles to convey them, friction between the rails and the bottle necks occurs along the entire length of the bottle conveyor path, which tends to damage the bottles.
Another problem occurs because the bottles are conveyed by an airflow, in that the conveyor speed can easily become unstable due to variations in the air pressure or the like, and this causes bottles that have been halted to be hit by bottles coming from behind, deforming them.
A further problem occurs in that there is likely to be dust in the airflow from the air blower, leading to the danger that this dust will be mixed into the interior of the hollow vessels, such as bottles.